<!DOCTYPE html>
<html>
	<head>
		<meta charset="utf-8">
		<title></title>
	</head>
	<style>
		*{
			margin: 0;
			padding: 0;
		}
		.ff{
			width: 90%;
			height: 50px;
		}
		.sss{
			border-style: solid;
		}
	</style>
	<body>
		<div class="ff"></div>
		<div class="sss"></div>
	</body>
</html>